diff options
| author | Stefan Hajnoczi | 2020-10-01 16:46:03 +0200 |
|---|---|---|
| committer | Stefan Hajnoczi | 2020-10-23 14:42:16 +0200 |
| commit | d9b495f9c6a943c9bbd50f7469efb645c23009c3 (patch) | |
| tree | d8ca95db872445d606fbe7eaa5577e99fa74d925 /qapi | |
| parent | block/export: add iothread and fixed-iothread options (diff) | |
| download | qemu-d9b495f9c6a943c9bbd50f7469efb645c23009c3.tar.gz qemu-d9b495f9c6a943c9bbd50f7469efb645c23009c3.tar.xz qemu-d9b495f9c6a943c9bbd50f7469efb645c23009c3.zip | |
block/export: add vhost-user-blk multi-queue support
Allow the number of queues to be configured using --export
vhost-user-blk,num-queues=N. This setting should match the QEMU --device
vhost-user-blk-pci,num-queues=N setting but QEMU vhost-user-blk.c lowers
its own value if the vhost-user-blk backend offers fewer queues than
QEMU.
The vhost-user-blk-server.c code is already capable of multi-queue. All
virtqueue processing runs in the same AioContext. No new locking is
needed.
Add the num-queues=N option and set the VIRTIO_BLK_F_MQ feature bit.
Note that the feature bit only announces the presence of the num_queues
configuration space field. It does not promise that there is more than 1
virtqueue, so we can set it unconditionally.
I tested multi-queue by running a random read fio test with numjobs=4 on
an -smp 4 guest. After the benchmark finished the guest /proc/interrupts
file showed activity on all 4 virtio-blk MSI-X. The /sys/block/vda/mq/
directory shows that Linux blk-mq has 4 queues configured.
An automated test is included in the next commit.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20201001144604.559733-2-stefanha@redhat.com
[Fixed accidental tab characters as suggested by Markus Armbruster
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'qapi')
| -rw-r--r-- | qapi/block-export.json | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/qapi/block-export.json b/qapi/block-export.json index 8a4ced817f..480c497690 100644 --- a/qapi/block-export.json +++ b/qapi/block-export.json @@ -93,11 +93,15 @@ # SocketAddress types are supported. Passed fds must be UNIX domain # sockets. # @logical-block-size: Logical block size in bytes. Defaults to 512 bytes. +# @num-queues: Number of request virtqueues. Must be greater than 0. Defaults +# to 1. # # Since: 5.2 ## { 'struct': 'BlockExportOptionsVhostUserBlk', - 'data': { 'addr': 'SocketAddress', '*logical-block-size': 'size' } } + 'data': { 'addr': 'SocketAddress', + '*logical-block-size': 'size', + '*num-queues': 'uint16'} } ## # @NbdServerAddOptions: @@ -233,8 +237,8 @@ { 'union': 'BlockExportOptions', 'base': { 'type': 'BlockExportType', 'id': 'str', - '*fixed-iothread': 'bool', - '*iothread': 'str', + '*fixed-iothread': 'bool', + '*iothread': 'str', 'node-name': 'str', '*writable': 'bool', '*writethrough': 'bool' }, |